Section 2: Approved Design Method

2.1 Introduction

The TxCRCP-ME design program and the AASHTO DARWin® 3.1 program
are available to department personnel through the district pavement
engineer. Consultants may obtain the TxCRCP-ME program from the
district pavement engineer or the Pavement Asset Management Section
of the Maintenance Division.

The AASHTO Guide also contains design procedures for rehabilitation
of rigid pavements, including asphalt concrete overlays or Portland
cement concrete (PCC) overlays of existing rigid pavements. Contact
the district pavement engineer or MNT – Pavement Asset Management
for further assistance.

2.2 TxCRCP-ME Design Program for CRCP

The design method was developed under department research
project 0-5832, “Develop Mechanistic/Empirical Design for CRCP.”
An elaborate three-dimensional finite element analysis was conducted
to identify the mechanisms of punchout distress in CRCP, and the
critical component that may cause the punchout distress was mechanistically
evaluated. A full factorial parametric study was performed for significant
input variables to compile the database of the analysis results. A
program was written using Microsoft Excel to perform the analysis
of the pavement system for given inputs in estimating the frequency
of punchouts, the primary structural distress in CRCP. The conversion
from mechanistic structural responses to pavement distress is achieved
by a transfer function determined empirically, utilizing data collected
from the department’s rigid pavement database project. The final
results of the software are presented in the form of charts and
tables.